1. Field of the Invention
This invention relates to a thermoplastic or thermoset article, a porous sheet, a paint composition, and a synthetic leather comprising a polyurethane resin with a memory shape or with a healable characteristics therewith, utilizable in the field of paint material, automobile parts material, machinery material, electric material, constructing material as filling, sealing and caulking, medical material, decorating material and clothing material.
2. Description of the Prior Art
It has previously been proposed to provide a resin article with a memory shape by several patented inventions. U.S. Pat. No. 4,193,899 to Lundberg et al discloses neutralized sulfonated elastomeric polymers derived from unsaturated elastomeric polymers such as EDPM terpolymers from substituted norbornen. U.S. Pat. No. 4,637,944 to Walker and U.S. Pat. No. 3,563,973 to Plainview et al disclose a ethylene polymer acquires a memory shape by a method of cross linking by energy irradiation. However, in the former prior art where the process of preparing the resin is not only complicated, but also it takes a long time for locking a shape and reversion to a memory shape. In the latter prior art, it requires too complex process such as cross-linking after shaping.
In regard to porous sheets, for instance, it is described in Japanese Pat. Publication No. 54-20557 that a porous sheet can be obtained from a polyurethane solution comprising a polyurethane obtained by reacting 4,4'-diphenylmethane diisocyanate and ethylene glycol and a organic solvent, by extracting the solvent from the solution on a substrate with a non-solvent. Whereas, this porous sheet has high permeability but very poor memory shape characteristics.
Referring to manufacturing methods of a synthetic leather with tough mar-resistibility, one of known methods described in Japanese Pat. Publication No. 59-21990 is to coat a solution of a high modulus modified acrylic polyurethane resin applied onto a substrate, and to remove the solvent component from the coated solution by drying. These synthetic leathers obtained by those method has a strongly mar-resistible characteristics, however, unfortunately, their healable characteristics is not so perfect as to revert back to their original unmarred surface once they are marred, scratched, or creased.
As for paint material, as it is described in Japanese Pat. Publication No. 49-38685, a polyurethane resin obtained by reacting 4,4'-dicyclohexylmethane diisocyanate, and polyethertriol obtained from trimethylol propane and propylene oxide is mixed with other paint components to make up a hard surface coating paint which is strongly mar-resistant after being applied, dried and cured. However problems thereby exist in that said paint practically non-healable and unable to remove completely any scratch given thereon.
Ordinary plastic and rubber articles have no specific of said memory shape nor healable characteristics. For example, an ordinary plastic can be locked in a reshaped form, but cannot revert back to its original shape by heating or the other simple method. And also, an ordinary rubber cannot be locked in a reshaped form at room temperature.